This invention relates to a network-based radio communication system such as the Internet, and provides an apparatus that can be connected to the Internet by radio signals and having a processing sequence for distributing push-type information to mobile terminals and a method for control of such a system.
In recent years, Internet-based push-type information distribution services are being provided. Such a push-type information distribution is meant to automatically deliver information at certain times from the host side to terminal devices as clients, but, in reality, the terminal device collects information from the host by requesting delivery of information at specific times. That is, in practice, the delivery method is operated not as a push-type control but as a pull-type control.
In the meantime, needs for mobile computing are increasing and contact to the Internet is currently carried out from the mobile terminal device. In mobile computing, a computer is connected to the Internet to exchange data using telephone network and the like. Because the transmission network is mobile telephone networks, it presents a feature that communication is possible from non-stationary locations such as automobiles and the like.
In order to distribute emergency information in real-time using such a pseudo push-type control that is in fact a pull-type control, it is necessary to output information delivery requests to the host at short intervals. When such information delivery requests are output to the host at short intervals, it leads to increase in the network traffic volume.
Also, when the client is a mobile terminal that can move to a different network for connection, it is necessary that the information delivered to the server managing this mobile terminal be reliably delivered to the server being connected to the mobile terminal.
Also, there is broadcasting service that simultaneously distributes identical information to all the devices connected to the network. The broadcasting service is not required to specify the addresses of each receiving device, and therefore, it is often used in the case of distributing important information to all devices simultaneously.
Although delivery of information by broadcasting can provide information from one device to many devices simultaneously, as far as the terminal receiving the information is concerned, there are times when all information broadcast are not needed by every terminal. For example, there is no need for the general public to receive information aimed at police and fire department during some disaster. However, police and fire departments should be aware of the information issued to general public. It is therefore preferable that broadcast information be distributed or received only by those needing the information.
However, because the conventional broadcasting technology can only distribute identical information simultaneously, there is a problem that it can not deliver the necessary information to people in need of that information. Also, there is a problem that, to deliver information needed only by the receiver, the conventional technology must individually deliver pieces of information.
Also, a client connected to a local area network (LAN), for example, is provided with an IP address defined within the LAN (referred to as a local IP address hereinafter). When this client is to communicate with a host server (referred to as an external server hereinafter) connected to the Internet, for example, this client must communicate using a global IP address.
In this case, if a client operating within a LAN that does not have an Internet IP address wishes to contact an external host, conventionally, when the external host receives such a request from the client, a router and the like having a network address translation (NAT) function selects a suitable IP address from a number of Internet IP addresses that are already under its management, and appropriately allocates this address to the client.
Then, in the case of sending data from the client to the external host, the router having a NAT function converts the originator""s IP address of data to an Internet IP address allocated from the local addresses of the clients, and, in the case of receiving data from the external host to be sent to the client, the sent IP address (that is, IP address allocated to the client) is converted to the client""s local address, to establish communication between the LAN clients and the external host.
However, in recent years, as mentioned earlier, push-type information distribution service is becoming available. But, it has not been possible to provide the push-type service to those clients operating with a LAN using the conventional technology.
This is because, in the case of a router with the NAT function, for example, because IP addresses are allocated in response to client access requests, it has not been possible to allocate Internet IP addresses to clients operating within a LAN in response to access request from the external host.
Also, in mobile computing, in the conventional communication devices, because the communication protocol is based on fixed communication devices, there is a problem that mobile devices cannot communicate by moving between the networks. Also, because telephone networks are used, there are problems that it takes some time for obtaining a connection and that access may not be possible when the line is being used by many users.
And, another problem is that when a terminal device moves from one site to another, addresses and other parameters of a server to be accessed may be different. The settings for a server that can be accessed by a mobile terminal are fixed in the individual terminals. When the mobile terminal moves in another network and use another servers, the existing settings of the terminal cannot be used.
Therefore, an object of this invention is to provide a radio communication system to reliably enable real-time distribution of push-type information to a mobile terminal device.
The object has been achieved in a push-type function server operating in a radio communication system comprised by a plurality of radio servers connectable to the Internet; at least one type of a function server connectable to the Internet; a base station radio connected to a radio server for radio communication with the server; a mobile radio for radio communication with the base station radio; and a terminal device connected to the mobile radio; so that the terminal device can connect to the Internet by radio communication with the mobile radio within a district managed by the base station radio connected to the radio server; wherein the push-type function radio server is comprised by:
an information accumulation section for storing information to be distributed to the terminal device, an identifier information for identifying the terminal device and a processing section; wherein the processing section is comprised by:
a mobile address information acquiring section for obtaining address information of a mobile radio connected to a destination terminal device from a home radio server that manages the mobile radio according to the identifier information; and
an information distribution section for distributing information to the radio server connected to the destination terminal device according to the address information.
Also, this invention enables the object to be achieved by providing a method for push-type control of the push-type function server according to claim 1, to perform the steps of:
acquiring address information of a mobile radio connected to a destination terminal device from a radio server that manages the mobile radio, based on the identifier information; and
transferring distribution information to a radio server connected to the destination terminal device according to the address information.
Also, this invention enables to achieve the object by recording the push-type control method disclosed in claim 16 on a computer-readable recording medium and installing the program into computer means so as to execute the prescribed steps.
As described above, according to this invention, address information of a mobile radio connected to a destination terminal device can be obtained from a home radio server that manages the mobile radio, by referring to the identifier information for destination terminal devices accumulated in the information accumulation section of the push-type function server, so that, based on the acquired address information, information to be distributed is transferred to a radio server connected to the destination terminal device. For this reason, even if the mobile radio and the terminal device connected to the mobile radio move to an operating district managed by a different radio server, the required information can reliably be delivered to the destination terminal device.
Additionally, according to this invention, the object is achieved by an information monitoring device operating in a radio communication system comprised by a plurality of radio servers connectable to the Internet; at least one type of a function server connectable to the Internet; a base station radio connected to a radio server for radio communication with the server; a mobile radio for radio communication with the base station radio; and a terminal device connected to the mobile radio; so that the terminal device can connect to the Internet by radio communication with the mobile radio within a district managed by the base station radio connected to the radio server; wherein the information monitoring device is comprised by:
an information monitoring section for detecting changes in information accumulated in other function servers; and
an information transfer section for sending a new piece of information in the accumulated information to the push-type function server according to claim 1.
Also, according to this invention, the object can be achieved by providing a method for push-type control of the information monitoring device according to claim 3, to perform the steps of:
detecting changes in information accumulated in other function servers;
building information to be transferred in accordance with the volume/content of the information; and
transferring the built information.
Also, this invention enables to achieve the object by recording the push-type control method for the information monitoring device disclosed in claim 3 on a computer-readable recording medium and installing the program into computer means so as to execute the prescribed steps.
As described above, according to this invention, because the system is designed so as to detect changes in information accumulated in other function servers and the differential information is sent to the push-type server, newly arriving information can be sent immediately to any destination terminal.